Results: Viewing Angle And Uniformity
The biggest advantage of IPS panels is their excellent off-axis viewing performance. There is very little degradation in both brightness and color accuracy until you’re well past the 45-degree mark. The photo below shows a 100 percent white field from five different angles.
We can see no perceptible difference between the AOC and ViewSonic monitors. Again, since they use the same LG panel, this is an expected result.
Arguably, these shots are the best reason to buy an IPS monitor. Off-axis image quality is excellent with only a slight falloff, and none of the color shift you'd see from a TN-based screens. Again, to do better, you'd have to use a plasma or CRT monitor.
While some monitors are better than others, all LCD panels have some degree of screen uniformity issues, and even samples of the same model can have quite a bit of variation. So, since there’s no solid standard for applying a rating to different panels, we’ll simply present the results of our measurements.
Both the AOC and ViewSonic monitors measure quite well, with only small differences in brightness from corner to corner. Zero percent and 100 percent fields are used, and nine points are sampled.
| AOC I2757Fh | ||
|---|---|---|
| Black Field Uniformity (cd/m^2) | ||
| .1304 | .2491 | .3576 |
| .2600 | .2330 | .1864 |
| .3339 | .3163 | .1025 |
| White Field Uniformity (cd/m^2) | ||
| 193.7727 | 205.1259 | 195.1854 |
| 185.4980 | 209.0425 | 204.3085 |
| 191.1678 | 192.7434 | 203.4475 |
| ViewSonic VX2770Smh | ||
|---|---|---|
| Black Field Uniformity (cd/m^2) | ||
| .1451 | .1587 | .1798 |
| .2218 | .2783 | .1221 |
| .5080 | .1656 | .2106 |
| White Field Uniformity (cd/m^2) | ||
| 171.0105 | 191.2719 | 159.7328 |
| 185.5074 | 201.0192 | 160.4003 |
| 193.1757 | 185.7181 | 181.6170 |
In a full-white field, the ViewSonic encounters slightly visible dark areas on both sides of the screen, though they’re imperceptible at lower brightness levels. A small bright spot is also evident in the lower-left section in a full-black field. Meanwhile, the AOC looks basically perfect to the naked eye.
Bear in mind, though, that different samples can appear and measure differently. So, by no means should this be taken as an absolute judgement.